Gear S3 Weather and S-Voice issues after upgrading S7 Edge to Nougat

I'm using a Galaxy S7 Edge with a Gear S3 Frontier (4G LTE, T-Mobile version). I recently updated my phone from Marshmallow to Nougat, and for reasons I can't remember I was asked to re-install my Gear Manager. This necessitated a light factory reset of my watch as well, so that I could re-pair the devices. Since then, my device has worked just fine with two notable exceptions: the weather app and S-Voice's ability to call or text my contacts.

When I try to perform the "add city" function in the stock weather widget, I get the usual note about giving the device permission to access my location. I then get a "finding location" dialog. However, it causes my phone to freeze up for a few seconds. I've tried going into the gear manager and accessing the settings for the weather app, and I get the same freezing behavior on my phone. It's as though any attempt to access my location on the phone weather app (except for using the phone desktop widget directly) fails.

Separate from this, when I try to text one of my contacts, I get a "contacts syncing" message, but my contacts never actually sync. I've read other messages on this forum in which people suggest connecting to wi-fi or LTE. I've tried this to no effect.

I just got the S3 Classic, and the weather is not working. I also have a nouget S7 Edge (Sprint). I tried getting it to work on the watch, and I allow it, and I get a "finding your location" on watch, and and a "Gear S plug-in has failed", "Restart app". This is the first post I have found relevant to the S3.

If I try to access the weather setting on the Gear app on the phone, the screen goes white, and never does anything. Same if I press the gear ⛭ next to weather.